Locking plug switch



Jan. 29, 1929.

H. HUBBELL LOCKING PLUG SWITCH Filed Dec. 30, 1925 3 Sheets-Sheet attouwqs Jan. 29, 1929. 1,700,437

|-|. HUBBELL LOCKING PLUG SWITCH Filed D60. 30, 1925 3 Sheets-Sheet 2 Jan. 29, 1929. 1,700,437

H. HUBBELL LOCKING PLUG SWITCH Filed Dec. 30, 1925 5 Sheets-Sheet 3 1 W I 65 W gammy/g H; n iimn 6565 63 4 5g :2

amvcufoz Patented Jan. 29, 1929.

UNITED STATES 1,700,431 PATENT OFFICE.

HARVEY HUBBELL, 0F BBIDGEPOBT, CONNEGIIOUT; LOUIE E. HUBBELL EXEOUTBIX OI SAID HARVEY IUBBELL, DECEASED.

LOCKING PLUG SWITCH.

Application filed December 80, 1985. Serial No. 78,418.

This invention relates to devices for detachably connecting the leads of electrical attachments to a source of power, and has for an ob'ect to provide an im roved connection 0 this character in WhlCh the ca blades can be engaged with and disengages from the receptacle contacts only when the receptacle contacts are dead contacts. Another object of the invention is to provide means for lockin the cap in the receptacle when the switc controlling the circuit through the receptacle and cap is in the closed position. A further object of the invention is to provide a device in which the receptacle is movable to operate the switch and also to control the locking means for the cap.

In carrying out my invention I provide a receptacle to receive the projecting blades of an attachment plu means for locking t e cap in the rece tacle while current is being transmitted to t e attachment to prevent accidental separation of the cap from the receptacle, and in which there is also a switch operated by movement of the receptacle which is in the open position when the cap is unlocked and is in the closed position only when the cap is locked so that the attachment plug cap is inserted into the receptacle to cause its contact blade to engage the contacts in the receptacle only when the contacts are dead, and can be removed only when these contacts are dead, and thus will eliminate the possibility of any arcing during the insertion or removal of the cap.

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawings forming a part of this specification, similar reference characters being employed throughout the various figures to indicate corresponding elements. In these drawings,

Fig. 1 is a vertical section through my improved receptaole and switch showing the cap in position in elevation, the elements being in positions where the cap is unlocked and the switch is open, the section being substantially on line 1-1 of Fig. 2.

Fig. 2 is a to plan view of the device with the cap bla es in section, the view being substantially on the plane of line 2-2 of Fig. 1.

Fig. 3 is a section similar to Fig.1 of a cap associated with sufiicient portion of the device to indicate how the cap is locked, in the rece tacle.

4 is a side elevation of t e cap.

Flg. 5 is a bottom lan view thereof.

Fig. 6 is a side e evation of the switch mechanism and the receptacle looking from the left of Fig. 1.

Fig. is a top plan view with the enclosing casmg and the locking ring removed.

1g. 8 1s a transverse section substantially on line 8-8 of Fig. 6.

Fig. 9 is a detail vertical section through the base and locking ring and the connection between the two.

Fig. 10 is a detail section through the lock and release mechanism for the switch, the section being substantially on line 10-10 of Fig. 13 and the elements being in the position the occupy when the operating spring is un er tension and the lock and release about to trip.

Fig. 11 is a similar section showing the elements at rest.

Fig. 12 is a side elevation looking from the left of Fig. 13, and

Fig. 13 is a vertical section substantially on the line 1313 of Fig. 11.

The device illustrated com rises a base 15 of insulating material a apted to be mounted on a wall, a anel or any other suitable support. Rigigly connected with this base is a locking ring 16 also of insulating material, rigidly secured to the base in suitable spaced relation by a pair of supporting members 17 and connected to the base and ring by the screws 18 and 19 respectively. Mounted on the base is a pair of upwardly extending metal posts 20 and 21 secured to the base b screws similar to the screws 18, and the base is provided with openin 22 leading to these posts for passage o the leads from the source of power, one of which is shown at 23, Fig. 1. These posts each carry a binding post screw 24 for attachment of these leads to this post. These posts 20 and 21 each carry spring contacts 25 and 26 respectively for engagement with the movable switch elements presently to be described. Also mounted on the base and diametrically opposite to the posts 20 and 21 are similar posts 27 and 28 which carry contacts 29 and 30 respectively to also engage the movable switch members. These posts 27 and 28 also carry spring contacts 31 and 32 respectively, spaced above the other contacts and engaging flat commutator rmgs 33 and 34' -respect1vely. It will be noted that these contacts 31 and 32 are double spring contacts so that they yieldmgly press against the opposite sides of the commutator rings to always insure a good electrical contact. These commutator rings are spaced from each other and also insulated from each other by mounting them on the insulating support 35 formin the body member of the receptacle. This ody member 1s a substantially cylindrical member and 1s mounted in the openin 36 in the locking ring 16. It is supporte on a rotatable shaft 37. This shaft is mounted to rotate in a bearing sleeve 38 mounted in the base 15.

The insulating body member 35 of the receptacle is provided with pockets or recesses 39 and 40, and it is provided in its upper end wall with slotsi 41 and 42 leading to these pockets respectively. These slots are adapted for entrance of the contact blades 43 and 44 respectively of the cap 45. Mounted in the recess or pocket 39 is a sprin receptacle contact 46 which is electrica y connected through the metal stud 47 to the commutator rin 34, and in the recess or pocket 40 is a s1milar receptacle contact 48 electrically connected to the commutator ring 33 through the rivet 49. The blade contacts 43 and 44 are connected to the binding st screws 50 and 51 respectively carned iiy the cap to which the leads 52 are connected in the .usual manner, these leads being to conduct current to any suitable attachment which is to be operated. It will be noted from Fig. 2 that the slot 42 extends substantially radiall of the rotatable body member 35 an also extends through one side edge thereof, while the slot 41 extends at right angles to the slot 42 and is spaced inwardly from the side edge. This arrangement insures that the proper blade contact 43 and 44 will be in; sorted in the proper slots and makes a polarized receptacle. The insulating ring'16 is provided with notches 53 which are arranged on diametrically opposite sides of the opening 36 through this ring, and they are so positioned that when the switch, presently to be described, is in the Off or 0 en position one of these notches will be 1n alignment with the slot 42 in the body member 35. It will be noted from Figs. 1 to 4 that the blade 44 of the cap is wider at its free end to provide an extension 54 extending radially outwardly of the cap and thus provides a shoulder 55. When the body member 35 is in a position so that the slot 42 is in alignment with one of the notches 53 the cap blades can be inserted in the slots 41 and 42, the extension 54 passing through the notch 53, and the blade 44 is of such a length that this extension passes entirely through the ring 16 to bring the shoulder 55 below the under side of this ring. It will be apparent that whenin this position the body 35 and the cap are free to rotate, and as soon as the body is rotated sufficiently to bring the extension 54 out of alignment with the notch 53 the cap is locked in the body member 35 by coaction of the shoulder 55 with the lower wall of the ring 16.

The switch illustrated is a double ole switch and comprises two movable switch blades 56 and 57. These blades are mounted on the support 58 and are insulated therefrom by the fibre bushings 59, and it will be noted that these contact blades are arranged at right angles to each other. The upper blade 56 is in position to bridge the contacts 25 and 30 of the posts 20 and 28, while the lower blade 57 is in osition to bridge the contacts 26 and 29 o the posts 21 and 27. The support 58, and therefore, the switch blade are mounted on a supporting block 60 which is rotated with a step by step movement to make and break the circuit by bringing the switch members 56 and 57 alternately into engagement with and se arate them from the spring contacts. This operating mechanism comprises a base plate 61 mounted in a recess 62 in the top of the base 15, and it is secured to the bearing sleeve 38. As it must be rigidly held against rotation it is provided with downwardly extending lugs 63 pro- 'ecting into recesses in the base to securely old this plate against any rotary movement. Also securely attached to this plate is a ratchet 64, in the present case having four shoulders 65 as the switch is operated through ninety degrees by each movement. The block 60 carrying the movable switch members is provided with a chamber 66 in which is mounted a coil spring 67 embracing the shaft 37. The block 60 is free to turn on this shaft and the upper end of the spring is rigidly secured to the shaft through the washer 68, while the lower end of the spring is secured to the block 60. The block 60 also carries a guide member 69 having downwardl extending flanges 70 at its opposite side e ges forming a guide for a locking plate 71. This plate is adapted to reciprocate in this guide and carries a downwardly extending stop lug 72 to enage the shoulders 65 on the ratchet 64. he locking plate has an opening 63 through which the shaft 37 extends, and one side of this opening is provided with a rack 74 meshing with a pinion 75 on the shaft which operates to reciprocate the locking plate as the shaft is operated.

The operation is as follows: Assuming the switch is in the position shown in Figs.

1, 2 and 6, it will be'noted that the switch isopen as the switch members 56 and 57 are not en aged with the stationary spring contacts. Tn this sition the blade slot 42 in the receptac e body member 35 IS in alignment with one of the notches 53 so that the blades of the cap 45 may be inserted in the receptacle to engage the receptacle contacts 46 and 48. It will be apparent that as the switch is open the contacts 46' and 48 are dead so that no current is carried to the attachment and the engagement of the blades on the cap is made to dead contacts. The 0 erator may now turn the cap 45 to the rig t or in a clockwise direction as indicated by the arrow in Fig. 2, and the blades 43 and 44 will turn the rece tacle body member 35 a quarter revolution in the same direction to bring the blades 43 and 44 to the dotted line position in Fig. 2. During this movement the spring 67 (Fig. 13) is wound or placed under tension because the block is held stationary by engagement of the stop lug 72 with one of the shoulders of the ratchet 64. During this movement the pinion 75 will shift the locking plate 71 laterally to the position shown in Fig. 10, and just before the end of the one quarter revolution the stop lug 72 will pass oil the outer end of the shoulder allowing the spring 75 to rotate the block 60 and with it the switch members 56 and 57 to bring them in engagement with the spring contacts 25 and 30 and 26 and 29 respectively to close the circuit. The switch members will be moved ninety degrees or a quarter revolution, and they will then be stopped by engagement of the stop lug 72 with the next shoulder 65 on the ratchet. This forward movement 0 erates through the rack and pinion 74 and 75 to return the locking plate to the holding position. It will be apparent from an inspection of Fig. 2 that while in this position the shoulder 55 is in alignment with the lower wall of the ring 16 and will lock the cap in position in the recptacle. The circuit is closed from lead 23 through contact 26 to switch blade 57, contact 29, post 27, contact 31, upper commutator ring 33, receptacle contact 48 and cap contact blade 44 to the leads 23. On' return through the blade 43, receptacle contact 46, lower commutator ring 34, spring contact 32, post 28, spring contact 30, switch blade 56, contact 25 and post 20 and out.

If the cap 45 is rotated a quarter revolution in the same direction the switch will be operated in the same manner with a snap action, it being held stationary by the lock and release mechanism until the spring 67 is wound, and it is then released to allow this spring to shift the contacts with a quick movement to give a rapid break. This movement to open the switch will bring the shoulder 55 on the cap blade 43 in alignment with the other notch 53 in the locking ring 16. The cap 45 may now be withdrawn from the recptacle. The mechanism may be enclosed in a suitable shell or casing 76 which should be lined with an insulating lining 77.

It will be apparent from the foregoing description that the blades of the cap can be inserted in and removed from the receptacle only when the circuit is open so that these blades are forced into or removed from engagement with the recetpacle contacts only when the receptacle contacts are dead, and, therefore, there is no chance of arcin during this operation. It will also be note that turning of the cap will turn the receptacle body to operate the switch which controls the current to the receptacle contacts, and the devices are so arranged that the circuit is closed only when the cap and receptacle are in the intermediate positions with the cap locked in the receptacle. Therefore, the cap cannot be removed from the receptacle or inserted in the receptacle when the switch is in the closed position. In this device the make and break is entirely between the switch elements, which, through the step by step operation described, gives a rapid make and break so that this device is adapted for use with a relatively heavy currents.

Having thus set forth the nature of my invention, what I claim is':

1. In a device of the character described, an insulating body member mounted for turning movement, said body forming a receptacle and carrying contacts for engagement with the blade contacts of an attachment plug cap, a pair of commutator rings carried by said member and connected to the respective contacts, contacts mounted on conducting supports and engaging the said rings, stationary switch contacts carried by the supports, movable switch contacts for engaging the stationary contacts, and means operated by movement of the body member for operating the movable contacts.

2. In a device of the character described, a base, an insulating ring mounted on the base, an insulating body member mounted to turn in the opening in the ring, said body member being provided with recesses and openings leading to said recesses, one of said openings opening through the side of the body member and the ring being provided with a notch in alignment with said opening in' one position of the body, receptacle contacts mounted in said recesses, a cap having contact blades arranged for insertion in said openings, to'engage the receptacle contacts, one of said blade contacts having a lateral extension to pass through the notch in the ring and provide a shoulder below the ring when the blades are in the body member, a switch arranged to control the current to the receptacle contacts, and means operated by movement of the body member to operate said switch, said switch being arranged to be in the open osition when the contact blade opening is in ali ment with the notch in the ring and is in 51: closed position only when this opening is not in alignment with the notch.

3. In a device of the character described, an insulating ring member, an insulating body member 'mounted in the opening in the ring, one of said members being mounted for turning movement relative to the other member, receptacle contacts carried by the bod member and adapted to engage the bla e contacts of an attachment plug cap, a switch for controlling the current to said contacts, means operated b a turning movement of the movable member for operating the switch, and cooperating locking means carried by the ring member and the cap arranged to lock the cap in the body member when the switch is closed and to release the cap when the switch is open.

4. In a device of the character described, an insulating ring member, a receptacle comprising an insulating body member mounted in said ring carrying receptacle contacts and having openings in its front wall leading to said contacts, one of said members being mounted for turning movement relative to the other, an attachment plug cap having contact blades for insertion in said openings to engage the receptacle contacts, and cooperating means carried by the cap and ring member for locking the cap'in the body member in predetermined relative positions of said member and to release the cap in another given position.

5. Ina device of the character described, an insulating ring member, a receptacle comprisin an insulating body member mounted in said ring carrying receptacle contacts and havin slots leadlng to said contacts, one of sai slots opening through the side of the body member, and the ring member being provided with a notch in alignment with said slot in a certain relative position of said members, one of said memhere being mounted for turning movement relative to the other member, an attachment lug cap having contact blades adapted to inserted in said slots to en a e the receptacle contacts, one of said 'b a es having a lateral extension to pass through said notch and providing a shoulder to en a 'e the inner wall of the ring member to I05: the cap in the rece tacle when the notch and slot are not in a ignment.

6. In a device ofthe character described, a stationary insulating ring member, a receptacle comprising an insulating body member mounted for turning movement in the ring member, receptacle contacts carried by said body member and said member being provided with slots leading to said contacts, one of said slots opening through the side of the body member, and said ring being provided with a notch in alignment with said slot in a certain position of the body, an attachment plug cap having blade contacts for insertion in said slots to engage the receptacle contacts, one of the blade contacts having a lateral extension adapted to pass through the notch and providing a shoulder to engage the inner side of the ring to lock the ea in the receptacle when the notch is out o alignment with the slot.

7. In an electrical device, an insulating ring member forming the front wall of the device, a receptacle body member of insu: lating material mounted for turning movements in said ring, said body having recesses and openings in its front wall leading to said recesses for passage of the contact blades of an attachment plug cap, contacts to engage said blades mounted in said recesses, said ring member having a notch in its inner wall, and an attachment plug ca having a lateral extension to ass throng said notch in one position of t e receptacle body and to engage the inner wall of the ring in another position of the body to retain the cap in the receptacle.

In testimony whereof I afiix my signature.

HARVEY HUBBELL. 

